These studies did not find relevant differences in the stellar populations of central galaxies in fossil and non-fossil systems. The imprint of monolithic collapse is not found, all the observations point towards the creation of FGs via the merging scenario, in which the gap is created via major mergers of M\(^*\)  galaxies. The possibility of the existence of a fossil phase in the life of a cluster is supported also by the presence of younger stellar populations in the centre of galaxy, probably due to recent major mergers with gas. In the top panel of Fig. REF  we show the relation between central velocity dispersion and central metallicity for a sample of ten FGs taken from [1]}, [2]}, [3]} and compared with the sample of normal and dwarf early-type galaxies of [4]}. In the lower panel of the same figure, the comparison is done for the central ages of the same samples. It can be seen that in both cases FGs are found in the same correlations as normal early-type galaxies. This plot again confirms that central galaxies in FGs are amongst the most massive known in the Universe.
